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Titre du document / Document title

Quantitative determination of hydroperoxides by Fourier transform infrared spectroscopy with a disposable infrared card

Auteur(s) / Author(s)

MA K. (1) ; DE VOORT F. R. V. (1) ; ISMAIL A. A. (1) ; SEDMAN J. (1) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) McGill IR Group, Department of Food Science and Agricultural Chemistry, Macdonald Campus of McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9, CANADA

Résumé / Abstract

Disposable polyethylene infrared cards (3M IR cards) were investigated for their suitability for the quantitative determination of peroxide value (PV) in edible oils relative to a conventional transmission flow cell. The analysis is based on the stoichiometric reaction of triphenylphosphine (TPP) with hydroperoxides to produce triphenylphosphine oxide (TPPO). Preliminary work indicated that the cards, although relatively consistent in their pathlength (±1%), had an overall effective pathlength variation of ±∼5%, caused by variability in loading of the oil onto the cards. This loading variability was reduced to <0.5% by developing a normalization protocol that is based on the peak height of the ester linkage carbonyl overtone band at 3475 cm-1, which allowed one to obtain consistent and reproducible spectra. The standard PV calibration approach, based on the TPPO peak height at 542 cm-1, failed because of unanticipated card fringing in the region where the measurements were being made. However, the development of a partial-least-squares (PLS calibration provided a means of eliminating the interfering effect of the fringes and allowed the TPPO band to be measured accurately. An alternate approach to the standardized addition of TPP reagent to the oil was also investigated by impregnating the 3M IR cards with TPP, thus allowing the reaction to take place in situ. The spectral analysis protocols developed (normalization/calibration) were programmed to automate the PV analysis completely. The 3M card-based Fourier transform infrared PV methods developed were validated by analyzing oxidized oils and comparing the PV predictions obtained to those obtained in a 100-μm KCl flow cell. Both card methods performed well in their ability to predict PV. The TPP-impregnated 3M card method reproduced the flow cell PV data to within ± 1.12 PV, whereas the method with an unimpregnated card was accurate to ±0.92 PV over the calibrated range (0-25 PV). Our results indicate that, with spectral normalization and the use of a PLS calibration, quantitative PV data, comparable to those obtained with a flow cell, can be provided by the 3M IR card. With the analytical protocol preprogrammed, the disposable 3M card provides a simple, rapid and convenient means of carrying out PV analyses, suitable for quality control laboratories, taking about 2-3 min per analysis.

Revue / Journal Title

Journal of the American Oil Chemists' Society    ISSN  0003-021X 

Source / Source

1998, vol. 75, no9, pp. 1095-1101 (15 ref.)

Langue / Language

Anglais

Editeur / Publisher

Springer, Heidelberg, ALLEMAGNE  (1947) (Revue)

Mots-clés anglais / English Keywords

Analysis method

;

Infrared spectrometry

;

Organic phosphine

;

Edible oil

;

Quality control

;

Oxidation

;

Lipids

;

Organic hydroperoxide

;

Quantitative analysis

;

Fourier transformation

;

Mots-clés français / French Keywords

Méthode analyse

;

Spectrométrie IR

;

Phosphine organique

;

Huile alimentaire

;

Contrôle qualité

;

Oxydation

;

Lipide

;

Hydroperoxyde organique

;

Analyse quantitative

;

Transformation Fourier

;

Mots-clés espagnols / Spanish Keywords

Método análisis

;

Espectrometría IR

;

Fosfina orgánica

;

Aceite alimentario

;

Control calidad

;

Oxidación

;

Lípido

;

Hidroperóxido orgánico

;

Análisis cuantitativo

;

Transformación Fourier

;

Localisation / Location

INIST-CNRS, Cote INIST : 204, 35400007058622.0060

Nº notice refdoc (ud4) : 2385684



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